1. Field of the Invention
The present invention relates to a high-frequency module integrating a high-frequency power amplifier circuit, a band pass filter, a high-frequency multiplexer circuit and the like, as well as to a communication apparatus, such as a mobile phone, which incorporates therein the high-frequency module.
2. Description of the Related Art
The mobile phones have been spreading wider in recent years, while improvements have been made in the function of the mobile phones and the services associated therewith.
In such a mobile phone, high-frequency signal processor circuits necessary for the construction of each transmission/reception system are mounted on a substrate.
In a general configuration of the conventional high-frequency signal processor circuit, a transmitting filter and a receiving filter are provided for switching between a reception signal inputted from an antenna and a transmission signal supplied to the antenna.
A radio signal inputted via the antenna is inputted to the receiving filter via a matching circuit provided at a fore stage of the receiving filter, the receiving filter selectively allowing the passage of the reception signal. The reception signal is amplified by a low noise amplifier before supplied to the signal processor circuit.
On the other hand, the transmission signal passes through the band pass filter thereby eliminating noises therefrom, the band pass filter allowing the passage of transmission signals in a predetermined transmission passband. The resultant signal is sent to the high-frequency power amplifier circuit. The high-frequency power amplifier circuit power amplifies the transmission signal before supplying the signal to the transmitting filter.
It has been a conventional practice to manufacture the transmitting and receiving filters, matching circuit, high-frequency power amplifier circuit, band pass filter and such as discrete components which are discretely mounted on an upper side of the substrate.
Unfortunately, if the individual special components are discretely mounted on the substrate, the apparatus is increased in size and costs.
Hence, there arises a demand for downsizing the whole body of the high-frequency module by miniaturizing/integrating as many miniaturizable circuit portions as possible.
It is therefore an object of the invention to provide a high-frequency module which can achieve the downsizing of the whole body thereof by forming a transmission line, an inductor and a capacitor, as components of the matching circuit, at an internal layer of a multilayered substrate, and to provide a communication apparatus incorporating the same.